To better understand chronic back pain, it helps to understand the anatomy of the back.

The back includes the spine and the structures that surround the spine. The spine is an upright row of stacked bones, called the vertebral column. Individual bones of the spine are called vertebrae. The vertebral column starts under the skull and continues to the buttocks.

Bones of the spine:

• Bones of the cervical, thoracic and lumbar spine
• Lower spine

The front of each vertebra is a round, solid cylinder of bone. Between each pair of vertebrae, a disk attaches to the bottom of the vertebra above it, and to the top of the vertebrae below it. The discs act as rubber cushions between the vertebrae. In addition, strong ligaments and muscles hold the vertebral column together. These structures support, surround, and protect the spinal cord.

Anatomy of the vertebrae, disks and muscles:

• The vertebral disks
• View of disks and ligaments
• Muscles of the back
• Disks and nerves

The back of each vertebra is an open ring of bone. Because the vertebrae are stacked on top of one another, the open rings form a tube that surrounds the spinal cord. The spinal cord is a thick bundle of nerves that starts at the bottom of the brain and continues down the spine. The spinal cord carries messages between the body and the brain. Nerves branch off of the spinal cord between each of vertebrae.

Spinal Cord Anatomy

• Front view of the spine and spinal cord
• Cross sectional view
• The conus medullaris is the end of the spinal cord in the back.
• The spinal cord ends in the lumbar spine at the level of L1 to L2
• The cauda equina is a bundle of nerves at the bottom of the spinal cord.
• Nerves of the cauda equina supply the bladder, rectum, perineum, and legs.